Tuesday, March 16, 2010

Pluto and the Kuiper Belt

We're getting waaay out there in astronomy. A little heavy maybe for elementary minds, but we still had fun with it. We read and made a notebook page as usual. Our book is dated 2006 and still has Pluto as a planet rather than a dwarf planet. So I had to do a bit if research to find the difference between the two. I don't remember where I found this definition:
"A dwarf planet is a celestial body that:
orbits a sun
has enough mass to give it a nearly round shape
is not a satellite of another object
has not cleared out all the objects in its own orbit."
A planet would meet the first three criteria and would also have cleared out all the objects in its orbit.
I found some interesting websites that helped the kids get a visual on the far reaches of our solar system.Here's a great solar system animation and a neat illustration of the Kuiper Belt. Science News for Kids describes and illustrates other dwarf planets and Sedna, "the most distant object known in the solar system."
I found this Labratory Impact Study done by Planetary Science Institute. Basically, they shot balls of ice with various projectiles to learn more about collisions of the icy Kuiper objects. I thought, "Hey! We could do that!" Maybe we couldn't be so scientific about it, but we could definitely learn a little about what happens during an ice collision. Plus, it would be fun!
First we froze bowls of ice in the freezer. After they were frozen, I added a little water to one bowl and inverted ice from another bowl on top and stuck it back in the freezer. This way we had semi-round objects resembling something from the Kuiper belt.

Examining the ice up-close.
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Here's where I turn this kitchen science experiment over to Jeremiah.
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The ice balls were set up on the deck rail. Jeremiah and the kids took turns shooting a BB gun through the open window. After each shot, Miah or Larkin would crawl out the window to inspect the damage. They tried pumping the gun a different amount of times for each shot, and they used the round BB's and the pointy pellets to see if they could get different results.
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Conclusion: Yep, that was fun!

Experiment number two came from this article on Crystalline vs. Amorphous Ice. Out to the Kuiper Belt, we find crystalline ice, which forms at a higher temperature than amorphous. In the Kuiper Belt, we find both kinds of ice. Amorphous ice freezes so quickly, that it doesn't have a chance to form any patterns. You can't find that kind here. But other materials can come in a crystalline or amorphous state. Sugar, for instance. And that gave us an excellent excuse to make rock candy. After getting everything set up for the rock candy, we made a second batch of the exact same sugar syrup, brought it to 300 degrees (hard crack stage), then poured it out into little circles.
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Although the temperature wasn't relevant in the experiment, the speed at which each sugar candy formed helped illustrate the formation of crystalline and amorphous ice. Amorphous ice and the amorphous sugar candy form quickly. Crystalline ice and the rock candy crystals form slowly in comparison. The experiment also allowed the kids to see (and taste!) what is meant by the terms, crystalline and amorphous.
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And lastly, we did the experiment in the book. We made ice cream to demonstrate the complexity of chemical reactions - specifically that salt lowers the freezing point of water, causing the water to melt and the cream to freeze.
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Sweet!


"Then the LORD answered Job . . .
'From whose womb comes the ice?
Who gives birth to the frost from the heavens
when the waters become hard as stone,
when the surface of the deep is frozen?'"
~Job 38:1,29,30

13 comments:

  1. Oh my Sarah, how amazing those experiments are. :) You have inspired me, yet again!!! :) xo

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  2. Thanks, Sarah, for the links and such. We have been studying space as well, but I was looking for some things for the younger boys to take part in. Looks like a lot of fun!

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  3. Yes, that was fun! Good for you--I'm in the time of year where 'fun school' is lost in the 'have to do school'. Thanks for the reminder!

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  4. Fun! Especially the shooting at ice part - my boys would be all over that...

    I kinda feel bad for Pluto, being demoted and such. Never mind the fact it's the farthest out there, all alone. Pluto's bullied on our Solar System playground... :)

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  5. Kudos to you. What brilliant inquisitive children you are rearing. Unfortunately my child went to public school (in Loudon county) and NEVER got the sort of education that stimulates the mind. If I only had it to do over again....but maybe one day with grandchildren

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  6. Instead of feeling bad for Pluto, people should realize that the controversial IAU demotion is not fact but just one viewpoint in an ongoing debate. In spite of the IAU decree, dwarf planets ARE planets too. Pluto is still a planet, as are Ceres, Haumea, Makemake, and Eris. Please do not blindly accept the controversial demotion of Pluto, which was done by only four percent of the International Astronomical Union, most of whom are not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. Stern and like-minded scientists favor a broader planet definition that includes any non-self-luminous spheroidal body in orbit around a star. The spherical part is important because objects become spherical when they attain a state known as hydrostatic equilibrium, meaning they are large enough for their own gravity to pull them into a round shape. This is a characteristic of planets and not of shapeless asteroids and Kuiper Belt Objects. Pluto meets this criterion and is therefore a planet. Using this broader definition gives our solar system 13 planets and counting: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris. At the very least, you should note that there is an ongoing debate rather than portraying one side as fact when it is only one interpretation of fact.

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  7. Thanks for your perspective, Laurele. I'll share this with my kids.

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  8. Wow Sarah, I am amazed at the photograph of the ice shattering, its fantastic! Looks like alot of fun was had by you all :)

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  9. Hi Sarah,
    Popped over from the Carnival of HSing. Wow. These are really cool...just up our alley.
    Blessings,
    Carol

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  10. How very fun! The BB gun experiment is inspiring me for ways to get my husband involved in the homeschooling. Thanks for sharing!

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  11. Awesome hands-on fun. A bb gun and ice cream. Could it get any better? Really? LOL

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  12. Great combo of hands on fun school! Thanks for sharing. I had never even heard of the Kuiper Belt before reading this. :)

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